Valve assembly for a filter device

ABSTRACT

A valve assembly for use in a filter device is disclosed herein. The valve assembly includes a valve housing, a cylindrical bore in the housing defining at least one open end, a valve stem inserted in the bore and including a groove about the circumference thereof, and a face plate mounted onto the housing about the open end in locking engagement with the housing. The face plate is provided with a cylindrical opening for receiving the valve stem, and a plurality of compressible fingers with gripping tabs about the distal end thereof which engage with the circumferential groove when the stem is inserted into the opening to create a fixed, rotatable relationship with the valve housing. The face plate also includes a locking tab which engages a recess in the housing to lock the face plate to the housing.

This is a divisional of Ser. No. 07/340,345 filed on 4-19-89, now U.S.Pat. No. 4,980,073, which was a continuation of Ser. No. 07/203,196filed 6/7/88, now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to a device for filtering impure liquids.More particularly, it pertains to a faucet-attachment water filterassembly together with a replaceable filter housing for filtering waterflow. The internally by-passable purifier apparatus permits theselective distribution from a common source of either purified ornon-purified water.

Various impurities, such as minerals, chlorine, and particulates, oftenenter domestic tap water to affect the taste, odor, appearance andhealthfulness of the water. A significant percentage of water obtainedfrom individual taps in the home and the like contains these chemicalconstituents in amounts that exceed limits set forth in standards issuedby public health services. In some cases, such samples evidence apotential danger. Various studies have identified a need for improvedsystems to control at least aesthetically undesired concentrations ofvarious minerals and other constituents as well as color, taste andodor. The problem is one of both preventing the transmission of diseaseor the like as well as overcoming effects that may be adverse to thesensibilities of the user.

In order to remove these impurities, point-of-use filtration deviceshave become increasingly popular in the home. These have includedin-line filters, under-the-sink filters, free-standing drink-sizeseparate filter units, and filter devices that attach to theconventional sink faucet or to the typical aerator secured thereto.

However, the addition of a water purifying apparatus has frequentlymeant the undesired occupation of counterspace, under-sink space orinterference to convenient utilization because of the need for flexiblehoses. In fact, to achieve comparatively low cost in such apparatus,manufacturers have been led to the production of units which attain thatobjective only at the expense of interference with space utilization oraesthetic unattractiveness.

Faucet-attachment types of water filters have become a viable commercialproduct, possibly by reason of the fact that they do not require changesin plumbing to allow their use in the home or similar environment. See,for example, U.S. Pat. No. 3,853,761 to McClory, U.S. Pat. No. 4,172,796to Corder, U.S. Pat. No. 4,359,384 to Brane, U.S. Pat. No. 4,504,389Rundzaitis, and U.S. Pat. No. 4,686,037 to Lang. Typically, they attachto the outlet of a faucet in the kitchen sink and include valving topermit flow of either tap or filtered water, the water to be filteredflowing through a replaceable cartridge mounted upon one portion of theappliance. The usual cartridge includes activated charcoal granules,impregnated carbon paper, or impregnated carbon cotton effective inremoving tastes and odors from the water.

However, this type of prior art device has had the disadvantages thatthe operation of the valve unit is not always reliable and tap waterleaks from the valve unit while purified water is being obtained, andthat the valve unit becomes unserviceable in a relatively short periodof time due to wear of the valve element disposed therein. In addition,the valve unit has been complicated in construction and hence difficultto manufacture, and the mounting of the valve unit on the faucet hasalso been difficult.

Equally important, many of the devices in the prior art have cartridgefilters that do not filter the water adequately and, moreover, requirethe entire water filter apparatus to be disconnected from the waterfaucet in order to replace the cartridge filter in the apparatus.Furthermore, the upward extension of the filter cartridge in a verticalplane above the is considered, by many consumers, to be aestheticallyunattractive.

In summary, prior art apparatus and filter mechanisms have not been asefficient as they might be, and they also have not led to efficienciesin manufacture. Furthermore, they have sometimes been aestheticallyunattractive for household use.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a new andimproved water purifying apparatus which overcomes at least many of theaforenoted disadvantages and otherwise undesirable features.

It is another object of the present invention to provide a new andimproved water filter housing that is readily replaceable as a unitarystructure, economical, discardable as a unitary structure when expended,and which through its own mechanical structure both simplifies andaugments the operation of its associated water purifying apparatus.

It is a further object of the present invention to provide an improvedwater filter that utilizes a replaceable, unitary filter housing and isinexpensive to manufacture, requiring less labor-intensive techniques,less material, and less costly tooling techniques.

It is a still further object of the present invention to provide a newand improved water purifier which is aesthetically pleasing wheninstalled in the home or even in a commercial or manufacturingenvironment.

Related to all of the foregoing objects, it is an aim to provide a newand improved water purifier that is significantly effective while beingeconomical of production, as well as an easily replaceable water filterhousing wherein the housing is completely detached from a stationaryvalve housing and discarded during replacement.

In accordance with one embodiment of the present invention, there isprovided a device for filtering impure liquids as a two-piece moldedconstruction utilizing the minimum amount of materials and partsnecessary to manufacture an effective, reliable apparatus. In itspreferred embodiment, the device is molded of high grade polystyrene, orother thermoplastic or thermoset resin. A valve assembly housing iscoupled in stationary fashion to a standard water faucet or the like. Afilter housing is detachably secured to the valve assembly for purifyingthe water supply from the water faucet. The valve assembly housing has araw water inlet in axial alignment with a raw water outlet. Acylindrical bore through the valve assembly housing defines a liquidflow passage outward to the filter. A valve stem is slidably receivedwithin the cylindrical bore to selectively divert fluid flow through thelateral flow passage. The valve stem has an radial conduit between andin alignment with the raw water inlet and raw water outlet to permit theflow of unfiltered water directly through the raw water outlet of theapparatus.

Exclusive from the radial conduit, the valve stem is partially taperedso as to direct the inflow of water from the raw water inlet through thecylindrical bore to exit the fluid outlet port. The fluid outlet portcommunicates in liquid-tight relationship with the fluid inlet port ofthe filter housing when the filter housing is secured on the valveassembly housing.

Water entering the filter housing through the fluid inlet portcirculates around the conduits formed between the filter materialpermanently fixed within the filter housing and ultimately passesthrough the filter material and becomes purified thereby. The water thenexits from the purified water outlet projecting from the lower cover ofthe filter housing. The fluid inlet port and fluid outlet port aredefined in correspondingly opposed positions of the sidewall of thefilter housing and valve assembly housing, respectively.

A diagonal groove is provided circumferentially around the valve stem inan S-type configuration between the tapered edge and radial conduitthereof. A resilient sealing member, in a corresponding S-ringconfiguration, is disposed in and throughout the groove so as to blockfluid flow to the tapered edge while permitting flow between the rawwater inlet and raw water outlet when the radial conduit is alignedtherebetween. The diagonal groove configuration allows for easierplacement of the S-ring on the valve stem during manufacturing, as wellas other functional advantages, as will be further described herein.

An alternative embodiment of a valve assembly housing comprises a faceplate which, during manufacture, is press fitted into place into an openend of the valve housing assembly. The face plate comprises a pluralityof compressible fingers, one of which has a locator pin integrallyformed thereon. When the face plate is press fitted, in a snug fashion,into the open end of the valve assembly, the compressible finger havingthe locator pin compresses inwardly until the pin snaps into lockingengagement with a pinhole formed in the valve housing. Thereafter, thevalve stem is inserted through a central opening of the face plate andinto the cylindrical bore of the valve housing. As the valve stem passesthrough the face plate, the compressible fingers compress awaytherefrom, allowing the stem's insertion. When the stem is fullyinserted, the tabs of the compressible fingers lock into acircumferential groove, in fixed rotating relationship, formed at oneend of the valve stem. As in the preferred embodiment, the valve stemhas an O-ring, radial conduit and S-ring thereon. The alternative valvestem assembly provides ease of manufacture and assembly and, hence,reduced costs. Once assembled, the valve stem can be easily, selectivelyoperated from a filtered position to a non-filtered position withoutconcern as to displacement of the valve stem and/or increased likelihoodof unserviceability due to complicated parts or mode of operation. Thealternative embodiment improves performance by reducing mechanicalproblems in component assembly, thereby providing further improvedconsumer performance.

The coupling means for removably connecting the filter housing to thevalve assembly housing forms a double-dovetail connection in twoperpendicular planes wherein the coupling element on the valve assemblyhousing flares outwardly toward the bottom thereof and has taperededges, creating a liquid-tight seal when joined to a correspondinglyshaped coupling receiving element formed on the filter housing. Thus, asimple snap-on/snap-off, liquid-tight connection is formed between thefilter housing and valve assembly housing for quick and easy replacementof the spent filter.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. The organizationand manner of operation of the invention, together with further objectsand advantages thereof, may best be understood by reference to thefollowing description taken in connection with the accompanyingdrawings, in the several figures of which like reference numeralsidentify like elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of the filtration deviceembodying the present invention;

FIG. 2 is a cross-sectional view of the device of the present inventionwith the valve at the non-filtered position;

FIG. 3 is a fragmentary cross-sectional view of the device of thepresent invention with the valve at the filtered position;

FIG. 4 is a top plan view of that shown in FIG. 2;

FIG. 5A is a fragmentary cross-sectional view of the coupling elementformed on the filter housing;

FIG. 5B is a fragmentary cross-sectional 5 view of the coupling elementformed on the valve assembly housing;

FIG. 5C is a fragmentary cross-sectional view of the coupling elementsjoined to each other;

FIG. 5D is an elevational view taken along 10 lines 5D--5D in FIG. 5B;

FIG. 6A is a top view of the coupling element formed on the valveassembly housing;

FIG. 6B is a bottom view of the coupling element formed on the filterhousing;

FIG. 7 is a cross-sectional view of a valve assembly housing of analternative embodiment;

FIG. 8 is a side view of a face plate used in combination with the valvehousing of FIG. 7;

FIG. 9 is a side view of a valve stem used in combination with thecomponents of FIGS. 7 and 8; and

FIG. 10 is a fragmentary cross-sectional view of the alternative valvestem and housing assembly in cooperating relationship.

DETAILED DESCRIPTION OF THE INVENTION

As specifically embodied herein and depicted in FIGS. 1 and 2, atwo-piece molded construction is provided having valve assembly housing1 and filter housing 2. Included within valve assembly housing 1 is rawwater inlet 3 which communicates with cylindrical bore 4 defining aliquid flow passage outwardly to filter housing 2. Valve stem 5 isrotatably disposed within cylindrical bore 4 and held in place byretaining pin 6 which extends up from the bottom of valve assemblyhousing 1.

As more clearly shown in in FIG. 3, pin groove 7 is formed around apartial circumference of valve stem 5 to engage with pin 6. Valve stem 5has plate 8 integrally formed thereon and at one end thereof abuttingagainst a corresponding end of valve housing 1. Knob 9 is in fixedattachment with plate 8 and provides a manual control to selectivelyoperate valve stem 5 semi-rotatably between a first (filtered) andsecond (non-filtered) position.

Distal from said end where plate 8 abuts with valve housing 1, there isformed on the valve housing a valve coupling element 10. Fluid outletport 11 is provided with in valve coupling 10 and communicates withcylindrical bore 4. Washer seal receiving groove 12 is formedcircumferentially around outlet port 11.

Filter coupling 13 is integrally formed on the sidewall of filterhousing 2 for intimate engagement with valve coupling 10. Fluid inletport 14 is centrally disposed within filter coupling element 13. Washerseal 15 is circumferentially positioned around fluid inlet port 14, andwhen the coupling elements are joined, seats in correspondingly shapedwasher seal receiving groove 12 of valve coupling 10. Thus, directalignment between fluid inlet port 14 and fluid outlet port 11 isformed, thereby creating a liquid flow passage from valve assemblyhousing 1 into filter housing 2 when valve stem 5 is in the filter mode.

Additionally, a watertight connection is formed between the fluid portswhen the coupling elements are joined, as the washer seal 15 iscompressed into the receiving groove 12. Further details with respect tothe operation of attachment will be provided later on herein.

Circumferential groove 17 is formed in valve stem 5 to receive O-ring16. O-ring 16 forms a washer-type seal to prevent water from flowing outto knob 9, as well as sealing valve stem 5 within cylindrical bore 4.

Radial conduit 18 is cut into valve stem 5 and capable of being alignedwith raw water inlet 3 when valve stem 5 is in the non-filtered position(see FIG. 2). Thus, radial conduit 18 serves to direct a water faucetsupply entering raw water inlet 3 directly through raw water outlet 19when non-purified water is desired. Valve aerator 20 is a commercialitem attached to the lower cover of valve assembly housing 1 in directalignment with raw water outlet 19 and functions to coalesce the waterflow.

Valve stem 5 is further provided with tapered edge 21 which, whenaligned with raw water inlet 3, deflects fluid flow through cylindricalbore 4 outward to fluid outlet port 11. Once therethrough, the fluidpasses into fluid inlet port 14 of filter housing 2 to be purified. Theabove is accomplished by rotating valve stem 5 to a position 90°different from that shown in FIG. 2 (i.e. see FIG. 3). FIG. 3 disclosesthe apparatus in the filter mode.

To complete a seal between tapered edge 21 and radial conduit 18, acircumferential S-shaped groove is diagonally cut into stem 5 so as tocompletely, circumferentially separate tapered edge 21 from radialconduit 18. A resilient S-ring 22 is then seated within thecircumferential S-groove.

Accordingly, S-ring 22 serves to block fluid flow to tapered edge 21while permitting fluid flow between raw water inlet 3 and raw wateroutlet 19 when radial conduit 18 is aligned therebetween in thenon-filtered position. Correspondingly, when valve stem 5 is in thefiltered position, S-ring 22 serves to prevent the possibility of fluidflow anywhere except down tapered edge 21 and out to filter housing 2.In this manner, raw water cannot accidentally leak around valve stem 5and out raw water outlet 19. Thus, if one desired to, for instance, filla jug with purified water, the raw water would not be able to leak outand mix with the filtered water. Furthermore, the proximity betweenS-ring 22 and 0-ring 16 provides for a maximum seal against backpressure when the valve stem is in the filtered position.

It will also be observed that S-ring 22 must travel by the point ofintersection between the walls of raw water inlet 3 and the longitudinalbore when valve stem 5 is turned from one position to another. As thispoint of intersection can create a sharp edge and damage S-ring 22, rawwater inlet 3 is provided with rib 23 (see FIG. 4) extendingthereacross. Rib 23 prevents S-ring 22 from pushing itself against thecorners of the aperture of raw water inlet 3 as S-ring 22 passesthereacross during rotation in valve stem position. In other words, rib23 creates a downward pressure onto S-ring 22 so that S-ring 22 avoidscontacting any sharp edge created by the intersection of the walls ofraw water inlet 3 and lateral bore 4, thereby preventing damage toS-ring 22.

Returning to the filter housing unit, filter housing 2 is formed byultrasonically welding lower cover 24 to upper cover 25 to form a singlemolded unit. Filter aerator 26 is integrally formed as part of lowercover 24. Permanently sealed within filter housing 1 is filter material27.

In accordance with the present invention, filter material 27 maycomprise activated carbon particles integrally mixed with a bondingagent, and the bonding agent and such carbon particles are formed into aself-supporting stable filter structure. The bonding agent may compriseany thermoplastic or thermosetting polymeric material, preferablysynthetic, which is capable of being shaped under the conditions ofprocessing to be utilized. Preferably, the bonding agent is a"thermoplastic material", by which is meant generally any polymericmaterial having thermoplastic properties and may include any syntheticor semi-synthetic condensation or polymerization product.

Consistent herewith, the activated carbon particles are intimately mixedwith the bonding agent particles and the particles providing the bondingagent are so selected that they have a size no less than, and preferablysubstantially greater than, on average, the particle size of theactivated carbon particles. After the activated carbon particles andbonding agent particles are integrally mixed until substantialuniformity of distribution is attained, the mixture is formed into asuitable structure with heat being applied to soften the bonding agentwhereby it adheres to the adjacent carbon particles and serves as abinder therebetween, thereby resulting in a porous plastic matrixstructure having entrapped therewithin the activated carbon particleswhich will perform the function of filtration of the liquid, especiallywater.

It may also be desirable to incorporate a filler and/or otherappropriate material(s) into the filter in order to, e.g., assist theactivated carbon in its filtration activity, or to impart a desiredproperty to the liquid.

Filter material 27 may occupy almost the entire volume within filterhousing 2, following the contours thereof. Alternatively, filtermaterial 27 may, for instance, be smaller than the space provided withinfilter housing 2 (see FIG. 2). Of course, the larger the filter surfacearea, the greater the filtering effect. To this end, filter material 27may be provided with inner and outer cavities 28 to increase theaforementioned surface area.

Additionally, as previously alluded to, filter material 27 ispermanently affixed to the interior of lower cover 24 by adhesive 29spread thereunder. Thus, fluid entering filter housing 2 is forced torun up and around the conduit 30 surrounding the top and sides of porousfilter material 27 and then pass therethrough before exiting throughfilter aerator 26. The combination of adhesive, filter housing size andfilter material design insures that incoming water received throughfluid inlet port 14 is uniformly distributed throughout the filtermaterial.

Accordingly, a simple and highly effective filter apparatus havingeconomy of manufacture and long-term durability is provided. Furtheradding to the convenience and novelty of this device is the uniquecoupling elements which allow for quick snap-on/snap-off filter housingreplacement.

Turning thereto, with reference to FIGS. 5 and 6, there is disclosed aunique coupling element for a water filtration device which provides adefinite water tight seal between valve assembly housing 1 and filterhousing 2, yet does not require the disassembly of numerous componentparts to replace the filter material, as required in prior art devices.Specifically, as shown more clearly in FIG. 5A, filter coupling element13 is downwardly tapered in its side view (i.e. edge thickness) and isprovided with an oppositely tapered valve coupling receiving area 31. Asshown in FIG. 5B, valve coupling element 10 is upwardly tapered andprovided with filter coupling receiving area 32, which is oppositelytapered thereto.

As is evident, valve coupling receiving area 31 is correspondinglyshaped to valve coupling 10 and, similarly, filter coupling receivingarea 32 is correspondingly shaped to filter coupling 13. Accordingly,filter coupling element 13 is capable of being intimately mated ontovalve coupling element 10 such that the correspondingly taperedcouplings will fit snugly into each other and filter housing 2 will befelt to snap onto valve housing 1 as washer seal 15 seats itself intowasher seal receiving groove 12, thereby creating a direct alignment andwatertight fit between fluid outlet port 11 and fluid inlet port 14 (seeFIG. 5C).

Referring to FIG. 5D, it is seen that the coupling elements are not onlyupwardly or downwardly tapered (as shown in FIGS. 5A and 5B), but thecoupling element is also outwardly flared so as to provide an even moredefinite fit and seal. FIGS. 6A and 6B more clearly show the couplingstructure design and relationship.

Specifically, FIG. 6A shows the upward taper and outward flare of valvecoupling element 10. FIG. 6B correspondingly indicates (from a bottomview) the downward taper and outward flare of filter coupling 13. Thisedge taper/face flare design in two perpendicular planes has beenlabeled a "double-dovetail".

The unique double-dovetail structure of the present invention providesfor tremendous ease in the removal of the disposable filter housing, aswell as a water-tight seal against leakage. It should be particularlynoted that, in the present invention, the entire filter housing (whichcontains a permanently fixed filter material) is discarded. To thecontrary, the prior ar teaches filter housing containing a filtercartridge which, in turn, contains a filter material. The filtercartridge is intermittently replaced within a reclosable filter housing,permanently attached to a valve assembly.

None of the foregoing, numerous operations are required with theapparatus of the present invention. A user merely snaps off the filterhousing, disposes it and snaps on a new filter housing. It can bereadily discerned that, not only does the present invention provide easyremovability of the filter, but also simpler parts and, therefore, fewermolding requirements.

Moreover, the convenience and ease provided by the present invention isfurther increased by the method of attachment of the apparatus to awater faucet supply. Specifically, faucet coupling 33, having interiorlythreaded collar 34, is provided on the upper cover of valve housing 1and centrally disposed around raw water inlet 3. Collar nut 35 holdsfaucet coupling 33 in centrally fixed attachment to raw water inlet 3,while permitting rotatable movement of faucet coupling 33 for removableattachment to a water faucet. Collar nut 35 has central bore 36 indirect alignment with raw water inlet 3 such that a water supply from afaucet can easily enter the water inlet. Thus, the ease of attachment ofthe device of the present invention is quite evident.

In particular, a user would merely remove a water faucet aerator andattach the valve assembly housing of the present invention onto thewater faucet by simply screwing the faucet coupling thereonto.Thereafter, a filter housing is quickly snapped onto the valve housingfor efficient and superior fluid filtration.

The preferred embodiment described herein provides, among other things,an inexpensive, easily manufactured, durable water filter for neareffortless use in the home environment. The two-piece moldedconstruction utilizes a minimum amount of materials and parts tomanufacture an effective, reliable filter unit.

FIGS. 7-10 depict an alternative embodiment of a valve assembly housinguseful with the present invention. Valve assembly housing 51 comprisesface plate 52 which, during manufacture, is press fitted into place ontoopen end 53 of valve housing assembly 51. Face plate 34 comprises aplurality of compressible fingers 54, one of which has locator pin 37integrally formed thereon. When face plate 52 is press fitted, in a snugfashion, into open end 53 of valve assembly 51, the compressible fingerhaving the locator pin 37 compresses inwardly until pin 37 snaps intolocking engagement with pinhole 38 formed in valve housing 51.Thereafter, valve stem 39 is inserted through a central opening of faceplate 52 and into cylindrical bore 40 of valve housing 51. As valve stem39 passes through face plate 52, compressible fingers 54 compress awaytherefrom, allowing the stem's insertion. When stem 39 is fullyinserted, tabs 41 of compressible fingers 54 lock into circumferentialgroove 42, in fixed rotating relationship, formed at one end of valvestem 39. As in the preferred embodiment, valve stem 39 has O-ring 16,radial bore 18, and S-ring 22 thereon. FIG. 10 represents the componentsof the alternative valve stem assembly in completed, locking engagement.

As is evident therefrom, the alternative valve stem assembly providesease of manufacture and assembly and, hence, reduced costs. Onceassembled, the valve stem can be easily, selectively operated from afiltered position to a non-filtered position without concern as todisplacement of the valve stem and/or increased likelihood ofunserviceability due to complicated parts or mode of operation. Thealternative equipment improves performance by reducing mechanicalproblems in component assembly, thereby providing further improvedconsumer performance.

While in the foregoing there is set forth a detailed description of onlyone particular preferred embodiment and alternative embodiment of thepresent invention, they must be considered simply as illustrative. Inthis regard, the scope of the invention is indicated by the followingclaims in view of the preceding description, and the claims are intendedto embrace all changes that come within their meaning and range ofequivalency.

What is claimed is:
 1. A valve assembly comprising:a valve housing; acylindrical bore in said housing defining at least one open end; a valvestem adapted for insertion into said open end and through said bore, thevalve stem including a groove about a circumference thereof; and a faceplate for mounting onto the housing about said open end in lockingengagement with the housing, the face plate including a cylindricalopening for receiving the valve stem in a fixed rotatable relation withthe face plate, the face plate further including a locking means to lockthe face plate to the valve housing, and a fastening means comprising aplurality of compressible fingers with gripping tabs about a distal endthereof which engage with said circumferential groove when said valvestem is inserted into said opening to create a fixed, rotatablerelationship with the valve housing.
 2. The valve housing of claim 1whereinthe locking means comprises a locking tab which engages with arecess in the housing to form said locking engagement.